Revert of Revert "Serialization of SkPictureImageFilter" (https://codereview.chromium.org/153583007/)

Reason for revert:
New SKPs with version20 are in Google Storage due to http://108.170.219.160:10117/builders/Housekeeper-Nightly-RecreateSKPs/builds/22

Original issue's description:
> Revert "Serialization of SkPictureImageFilter"
>
> This reverts commit 227321b30106e57942929eb96fa5bc22544f6c9e.
>
> Revert "Sanitizing source files in Housekeeper-Nightly"
>
> This reverts commit baf28584b7636c01355f8d8d972e06aa7fb66d77.
>
> TBR=robertphillips@google.com,sugoi@google.com
>
> Committed: https://code.google.com/p/skia/source/detail?r=13356

R=robertphillips@google.com, sugoi@google.com, fmalita@google.com, fmalita@chromium.org
TBR=fmalita@chromium.org, fmalita@google.com, robertphillips@google.com, sugoi@google.com
NOTREECHECKS=true
NOTRY=true

Author: rmistry@google.com

Review URL: https://codereview.chromium.org/143163005

git-svn-id: http://skia.googlecode.com/svn/trunk@13357 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/effects/SkPictureImageFilter.h b/include/effects/SkPictureImageFilter.h
index eeaf1d2..a10d23e 100644
--- a/include/effects/SkPictureImageFilter.h
+++ b/include/effects/SkPictureImageFilter.h
@@ -28,7 +28,13 @@
 
 protected:
     virtual ~SkPictureImageFilter();
-    explicit SkPictureImageFilter(SkReadBuffer& buffer);
+    /*  Constructs an SkPictureImageFilter object from an SkReadBuffer.
+     *  Note: If the SkPictureImageFilter object construction requires bitmap
+     *  decoding, the decoder must be set on the SkReadBuffer parameter by calling
+     *  SkReadBuffer::setBitmapDecoder() before calling this constructor.
+     *  @param SkReadBuffer Serialized picture data.
+     */
+    explicit SkPictureImageFilter(SkReadBuffer&);
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
     virtual bool onFilterImage(Proxy*, const SkBitmap& src, const SkMatrix&,
                                SkBitmap* result, SkIPoint* offset) const SK_OVERRIDE;